Shelf handling and forming apparatus



Feb. 21, 1967 M. E. HANDLER SHELF HANDLING AND FORMING APPARATUS 3 hets-sheet 1 Filed Aug. 19, 195

m T N E V m 1967 M. E. HANDLER SHELF HANDLING AND FORMING APPARATUS 5Sheets-Sheet 3 Filed Aug. 19, 1964 MILTON E. HANDLER ATT'Y United StatesPatent 3 304,760 SHELF HANDLTNG A ND FQRMING APPARATUS Milton E.Handler, Evanston, Ill., assignor to Hlrsh Mfg. Co., Skokie, 111., acorporation of Illinois Filed Aug. 19, 1964, Ser. No. 390,647 11 Claims.(Cl. 72324) The present invention relates to shelf handling and formingapparatus and has particular reference to a fully automatic high speedapparatus for shaping the lateral end edges of sheet steel blanks whoselength is cut crosswise from commercially supplied unslit or mill-edgeprefinished coiled steel and which are ultimately formed into generallyrectangular shelves marginally reinforced on all four sides and adaptedat their corners for squared attachment against corner posts in theassembly of knockdown steel shelving units.

The shelf handling and forming apparatus of the present invention isessentially of the roll forming type wherein the side edges and then theend edges of the blanks are turned progressively out of the plane of theblank by means of a series of forming rolls, the net effect of which isto produce, on all four edges, marginal reinforcing flanges which notonly reinforce the shelves but also, in part, constitute attachmentmeans whereby the shelf flanges solidly engage two sides of each cornerpost when they are assembled in a shelving unit.

The specific character, i.e., shape, of the flange formed by theapparatus of the present invention may vary from simple right angle bendmembers to compound flanges preferably having one or more re-entrantbends, ultimately producing, if desired, a closed box-type marginalreinforcement. Irrespective however of the particular shape which isapplied to the four edges of the shelf blanks undergoing formation, theessential features of the invention remain substantially the same.

The shelves which are produced by the apparatus of the present inventionare essentially of elongated generally rectangular design. In theirfinished form, the shelves are shown marginally reinforced by compoundflanges along their longitudinally extending side edges, as well as bycompound flanges along their shorter transverse end edges. An example ofa shelf of this general type, and one which is capable of being, inpart, formed by the apparatus of the present invention has been shownand described in a copending application of Irwin W. Ferdinand and DaleR. Lopatka, Serial No. 368,634, filed May 19, 1964, now abandoned, andentitled Knockdown Steel Shelving Unit and Corner Fastening MeansTherefor.

In shaping rectangular panels or blanks into shelves of the type shownand described in the above mentioned application with roll formingequipment, considerable difliculty has been encountered in rolling theshort end edges of the blanks to produce exactly dimensioned compoundflanges along such edges. Whereas, during formation of the long sideedges of the blanks to produce the longitudinally extending compoundflanges, simple edge guides are effective to hold the blanks inlongitudinal alignment with the progressive forming rolls, both duringentry of the blanks into the rolls and during travel therethrough, suchedge guides cannot be relied upon to hold the blanks straight and inalignment with the rolls when the short side edges of the blanks areundergoing shaping. The factors which contribute toward blankmisalignment are manifold and are based upon a combination of physicalfactors, many of which have an economic origin in connection with themanufacture of steel shelving and particularly from coiled stock.

It is understood that a relatively long rectangle of sheet metal, Whoseside edges are to be rolled, can be fed endwise between opposing seriesof flange edgeforming rolls with fairly accurate alignment of the blankwith the rolls maintained by the use of guides on opposite sides of thestrips. The comparative long length of the edge guides between the firstand last roll forming stations and the short cross distance betweenopposing side edge guides provides a geometric vectorial relationshipthat leaves little opportunity for misalignment, cocking or binding ofthe blank in the guides. On the other hand, where a relatively short butwide blank is concerned, i.e., short in its longitudinal direction oftravel, and wide between opposing guides, particularly where the widthof the blank is relatively great, i.e., long in a direction transverseto its directionof travel, it is essential that the blank be fedsquarely to the first pair of forming rolls so that its end edges areengaged by such rolls simultaneously. Otherwise jamming or binding ofthe blank is apt to occur when close guide tolerances are maintained,the first pair of rolls to engage one of the end edges of the blank willadvance that end edge before the opposite pair of rolls engages theother end edge of the blank and a cocking of the blank will occur thatwill pass the blank obliquely through the entire set of forming rollsWith the result that the shelf formed is not square at its corners andwill not square up with the shelf support columns along with shelvesthat are square at their corners. These difficulties prevail even whenclose tolerances in the transverse width of the blanks are maintainedand are greatly augmented when the blanks are stamped crosswise frommill run strip steel. Moreover, in forming steel shelving by a rollforming operation, numerous other factors are involved in the properhandling and guiding of the-shelf blanks to and through the variousforming stations without darnage to the finish of the precoat on thestrip stock. Many of these factors are determined by and have aneconomic significance as will be described presently.

In mass production of steel shelving as an automatic continuous process,it is more economical to purchase mill run, prefinished coiled sheetsteel Whose width is the length of the shelf blank and pass it throughthe shelf-forming mill at this width rather than incurring the addedexpense of marginally trimming or slitting it to an exact widthdimension. The blanks are stamp cut from the coiled strip as fed andtherefore have a closely held width tolerance. They are passed l'engthwise through a first forming mill section and the longitudinal sideedges thereof are formed to produce the marginal side flangestherealong. The blank is then passed laterally through the second orfinal forming mill section for shaping the short end edges of the blankwhere there is apt to be a discrepancy of as much as 30 or 40thousandths of an inch in the length of the blanks which occur due tovariations in the width of the mill run strip. Thus, with wide guidetolerances provided to allow for this discrepcancy the forming rolls onone side of the forming mill are presented quite frequently With morematerial than the forming rolls on the other side thereof. In such aninstance, even though bot-h end edges of the blank arrive at and aretheoretically engaged by opposing pairs of forming rolls precisely atthe same time, the peripheral speed of roll engagement of the blank atits end edge that contains the most material will be greater than theperipheral speed of roll engagement along the other edge. This is due tothe frusto-conical shape of the first forming rolls where the peripheralspeed increases with the increasing diameters nearer the major base ofthe cone frustum. Since one end edge of the blank is thus driven at agreater speed than is the other end edge, the tendency for the blank isto become cocked so that it will pass obliquely through all of theforming rolls in the second mill, or else become jammed between the edgeguides. These considerations are particularly applicable and blankjamming is an especially prevalent factor when the forming rolls aregrip blasted to increase the frictional characteristics thereof and whenthe steel material of the blank is prefinished and waxed so that it isextremely slippery and is gripped only at its edges to avoid damage tothe finish.

From the above discussion it will be apparent that proper guiding of theblanks to and through the second forming mill where the short end edgesof the blank are formed, and particularly to and through the opposingpairs of forming rolls at the first station of the end forming mill, isessential to the successful forming of compound flanges along the shortedges of the blanks. Because of the wide tolerances required and therelatively short length of the blank ends arriving at the second formingmill, the use of edge guides alone does not prevent cocking or twistingof the blanks at or in the vicinity of the second forming mill. Thegreater driving force exerted by one pair of forming rolls on one sideat a given station will invariably be encountered and it is a purpose ofthe present invention to nullify the effect of such unequal drivingforces and hold the blanks to a true longitudinal course as they pass toand through the second forming mill, even in a direct relationshiprelation to their existence.

The invention is thus designed to overcome the abovenoted diflicultiesand to utilize the character of the polish finish to assist therein toprovide an improved blankfeeding and blank-guiding apparatus andmethods, for blanks whether made from slit or unslitted strip steelstock but particularly where shelving blanks that have been formed alongtheir long side edges in a first forming mill are fed to a second millfor formation along their short end edges.

In carrying out the invention, special and novel guide means areprovided on the entrance end of the second forming mill to assure asquare entry of the blanks into the first stand of the mill. The guidemeans includes opposing guides which cooperate under close toleranceswith the square ends of the compound flanges just formed along thelongitudinal edges of the blanks. These longitudinal flanges nowextending transversely of the direction of travel of the blanks to thesecond forming mill are made with identical lengths as determined by thestamping operation.

The guide means also include bottom guides to support the laterallyprojecting end edges of the blank which initially lie in the plane ofthe blank. Such bottom guides engage only the end portions of the blankand align them in a plane tangent to the bite of the opposing pairs ofrolls at the first station of the mill. The guide means also include topguides which cooperate with the laterally projecting end edges of theblank and hold the panels down as they progres toward and enter betweenthe rolls of the first station of the mill. These guides are designed topresent the blanks to the first stand of the forming mill with extremeaccuracy of alignment, i.e. so that both side edges of the blanksapproach the rolls of the first stand of the mill together. Then, inorder to maintain this accuracy of alignment for the passage of theblanks through the forming mill, the rolls at the first are soconstructed that they do not bend the end edge of the blank butpreferably have cylindrical blank-gripping surfaces which exert noforming function whatsoever upon the blanks. In effect, these firstrolls preferably are simply blank-gripping and power-feeding rolls. Thepressure they exert upon the blanks is considerable so that they willresist slippage of the blanks therebetween and counteract any tendencyfor the blanks to cock or twist after they have been engaged by thefirst forming rolls. These latter rolls constituting, in, effect, thefirst forming rolls of the series of forming rolls at the second formingmill.

It is an accomplished fact that where a given blank is of suflicientlength to enable the forming rolls of at least three successive stationsto be in simultaneous engagement with the side edges of the blank,longitudinal alignment of the blanks passing through the mill mayreadily be attained and no problem of accurate tracking presents itself.However, where a given blank is of such short longitudinal extent in itsdirection of travel that less than three stands may simultaneouslyengage the side edges thereof, then blank width must be exact and thedriving forces which propel the blank through the mill must be verycarefully controlled lest the tendency for the blank to twist occasionsjamming of the machine. Where blank width is not controlled by reason ofpurchase of the sheet material at mill width instead of slitting it toexact width, edge guiding of the blank, no matter how carefullyper-formed, is totally ineffective to keep a blank from twisting afterthe first forming rolls have engaged the blank.

The tendency for a blank to twist in one direction or another, or not totwist, is not a matter of chance. If one side edge of a blank projectslaterally a greater distance than does the other side edge, invariablyand without exception the longer projecting side edge will be pulledforwardly at a greater rate than will the other side edge and no amountof care in guiding the blank before it arrives at the first formingstand, can induce the blank to maintain or recover its alignment inpassing through that station. The passage of a blank through the firstforming station is regarded as an exception rather than as the rule.

According to the present invention, and as heretofore indicated, byfeeding relatively short blanks to the first effective pair of formingrolls of the forming mill by pairs of gripper rolls which are trulycylindrical and exert no forming function on the edge regions of theblank, the trailing regions of the blanks are still engaged by thegripping rolls at the time that the first forming rolls seize the blank.With careful guiding of the blanks at the approach to the gripping rollsthere are no factors associated with such gripping rolls tending tomisalign the blanks, regardless of whether one side edge thereofprojects a greater distance laterally than does the other side edge. Infact if one end projects further than the other it is proportionallygripped by the gripping rolls. There are no conical gripping surfaces onthe gripping rolls to increase the linear speed of either end edge ofthe blank. Once engaged by the gripping rolls, the blanks are held totheir initial alignment even until the leading edges of the blanks areengaged by the second set of forming rolls. The gripping rolls are stilleffective along the trailing regions of the blanks to counteract anytendency for the blank to twist. By the time that a blank has progressedsufiiciently far into the mill that the gripping rolls release thetrailing edges of the blank, the leading edge of the blank has beenformally engaged and advanced some distance by the second pair offorming rolls at the third station and, thereafter, the problem of blankmisalignment has been resolved due to the rigidity which has beencreated along the edges undergoing forming by reason of the bendsimposed thereon. In fact beyond the second length one end edge of theblank has been moved to a position where such imposes little if anycocking action on the blank.

Apart from the matter of attaining proper tracking of the shelf blanksto and through the first set of forming rolls in the second forming millwhere the short end edges of the blanks are shaped to their flangedcondition, the present invention is concerned with a novel means andmethod whereby an originally rectangular blank may be initially shapedas to its contour in an improved manner and then fed longitudinallyendwise, i.e. in the direction of its longest extent, to and through afirst forming mill wherein the longitudinal side edges of the blank areshaped or flanged by a downward rolling operation. The blank is theninverted and fed sidewise, i.e. in the direction of its short dimension,to the second forming mill wherein the transverse end edges of the blankare shaped or flanged by an upward rolling operation.

The initial blank-shaping operation includes the removal of metal by anotching operation at the four corners of the originally rectangularblank so that after the formation of flanges along the longitudinaledges of the blank in the first forming mill no metal is raised whichwould obstruct the formation of flanges along the transverse end edgesof the blank in the second forming mill. Stated otherwise, the inventioninvolves a novel means and method of shaping and handling an originallyrectangular blank so that after marginal side flanges are formed alongits longitudinal side edges, open corners are provided at the ends ofthe blank so that the thus formed side flanges will clear the formingrolls which are employed in the formation of similar marginal flangesalong the end edges of the blank. In both instances the prefinishedblank is pressure contacted only along the flange areas. In this manner,the work performed by the side edge forming rolls in the first mill willbe independent of the work performed by the end edge forming rolls inthe second mill, yet the flanges will be square to each other and thelatter will not deform or otherwise disturb any material previouslyformed by the first mill.

The provision of a fully automatic apparatus for and method of shapingthe short lateral end edges of sheet metal blanks in the production ofshelf units as briefly outlined above being among the principal objectsof the invention, numerous other objects and advantages will readilysuggest themselves with the following description.

In the accompanying three sheets of drawings forming a part of thisspecification, one illustrative embodiment of the invention has beenshown.

'In these drawings:

FIG. 1 is a perspective view, entirely schematic in its representationof a shelf forming and handling apparatus embodying the principles ofthe present invention;

FIG. 2 is a perspective view of one exemplary form of a marginallyreinforced shelf constructed according to the method and apparatus ofthe invention;

FIG. 3 is a plan view of a blank from which the shelf of FIG. 1 isformed;

FIG. 4 is a fragmentary perspective view of a portion of the shelfforming apparatus illustrating the manner in which partially formedshelf blanks are conducted from the first forming mill, inverted andredirected to the second forming mill for further forming operations;

FIG. 5 is a fragmentary perspective view of a portion of the shelfforming apparatus in the vicinity of the second forming mill andillustrating specifically certain blank impelling and edge guiding meansemployed in connection with the present invention;

FIG. 6 is a fragmentary sectional view taken substantially along thevertical plane represented by the line 66 of FIG. 5 in the direction ofthe arrows;

FIG. 7 is a fragmentary sectional view taken substantially along thevertical plane indicated by the line 77 of FIG. 5 and in the directionindicated by the arrows; and

FIG. 8 is a fragmentary sectional view taken substantially along thevertical plane indicated by the line 3-45 of FIG. 5 and in the directionindicated by the arrows.

Referring now to the drawings in detail and in particular to FIG. 1,there has been disclosed in this view in an entirely schematic manner,an apparatus for forming steel shelves such as the shelf 10 shown at theextreme right hand end of the view and also in FIG. 2. While theapparatus of FIG. 1 is adapted, by modification or interchange ofcertain forming rolls associated therewith, for the construction of awide variety of generally rectangular shelves, the shelf 10 has beenselected for illustration herein as being exemplary of at least oneparticular shelf configuration capable of being effectively formed bythe apparatus.

Specifically, the shelf 10 is of the type shown and described in theabove-mentioned patent application, Serial No. 368,634 and reference ishereby made to such application for a full understanding of the natureof the shelf and of its use. Briefly however the shelf is designed forused, in conjunction with other like shelves, in connection withknockdown steel shelving wherein the shelves are removably secured attheir corners to vertical corner posts. The shelf 10 is generally ofrectangular configuration and it includes a horizontal planar bodyportion 12 having downturned longitudinally extending marginal compoundside flanges 14 and downturned transversely extending marginal compoundend flanges 16. The side flanges 14 are provided with narrow inturnedrim flanges 18 which terminate in upturned reentrant flanges 20. The endflanges 16 are provided with narrow inturned rim flanges 22. The upperedges of the flanges 14- project above the plane of the body portion 12and are connected to the body portion by narrow rim flanges 24 andvertical offset flanges 26, the latter preventing objects from rollingor sliding from the shelf. Each of the four corner regions of the shelf10 is notched out as at 28, thus exposing the squared ends of theflanges 14 and 16 for reception therein of a corner post (not shown) bymeans of which the shelf 10 may be assembled in a shelving unit, all ina manner set forth in the above mentioned patent application. The shelfIt) is adapted to be formed by the apparatus of FIG. 1 from a blank suchas the blank 30 (FIG. 3), this blank being of rectangular design andhaving notched corners 32 which establish the previously mentionednotched out corners 28 of the completed shelf 10' and which also serve afunction in connection with the formation of the end flanges 16 by theapparatus of FIG. 1 and a squaring engagement between shelf flanges andcorner posts.

It is to be noted that the shelf 10, as well as the blank 30 from whichit is formed is of elongated design and that its longitudinal extent isseveral times greater than its transverse extent. Thus, the flanges 14are formed from late-rally projecting elongated narrow strip portions 34which are partially outlined by dotted lines in FIG. 3, while theflanges are formed from laterally projecting relatively short stripportions 36 which likewise are partially outlined by dotted lines.

Referring again to FIG. 1, the shelves 10 are successively formed fromfinish-coated mill run coiled steel 40 which passes through straightenedrolls 41 and from thence to a punch press 42 where the notched blanks 30are formed. The notched blanks are then conducted endwise, i.e. in theirlong direction, along a conveyor section 44 to a first mill 46 where theelongated narrow strip portions 34- thereof are operated upon by aseries of successive forming rolls to produce the marginal side flanges14 and 16, these flanges being turned downwardly out of the plane of theblank by the rolls 48. Due to the relatively great length of the stripsin their direction of travel, little or no difliculty is encountered inblank alignment with the forming rolls. Additionally, since the blanksare cut by the punch press 42 to proper width, the lateral stripportions which supply the metal for the flanges 14 are substantially ofequal and constant width on opposite sides of the blanks so that thereis little if any tendency for one pair of forming rolls to engage moremetal than the other pair of forming rolls on the opposite side of thestrip and thus equal driving speed will obtain on both sides of theblanks as they pass through the first forming mill 46. Still further,the relatively great length of the blanks will permit many stations ofthe first forming mill 46 to operate upon the strip simultaneously sothat the strip is held securely in proper longitudinal alignment.

The disclosure of FIG. 1, being entirely schematic, no attempt has beenmade to disclose therein all of the blank handling devices andinstrumentalities associated with the machine other than those describedherein. For example, the details of the various pairs of forming rollsat the successive stands of the first forming mill 46, the drivingmechanism for this mill or for the illustrated conveyors, the drivingmechanism for the turn-over device 50, the numerous electric controlsfor such instrumentalities have been omitted from the disclosure sincethey are not directly involved in the invention disclosed and claimedherein other than the length of the blank varying with wide tolerancesin mill run strip width. The stamping and notching of the blanks by thepunch press 42 as shown in FIG. 1, the manner in which the partiallyformed blanks are conducted, and especially the manner in which they areguided to the turn-over 50 are subject matter covered elsewhere. Thisinvention is essentially concerned with the turn-over, the blankdelivery to the second forming mill 60, and the nature of the firstseveral stations of the second forming mill 60 which constitute thesalient features of the present invention and they have been illustratedin detail in FIGS. 4 to 8 inclusive.

From the first forming mill 46, the blanks are then conducted to ablank-inverting and direction-changing station where a turn-over devicein the form of a rotary rack 50 having radial arms 52 receives theblanks and inverts them by flipping them over and onto a conveyor 54which conducts them to a second conveyor 56, the latter being driven intimed relation with a second mill 60 which receives the blanks from theconveyor 56 and, by means of a series of successive forming rollsoperates upon the short strip portions 36 and shapes them into the formof the flanges 16, thereby completing the finished shelf 10.

Whereas, in connection with the first forming mill 46, guiding of thestamped formed elongated blanks through the mill endwise with closetolerance edge guides provides a proper tracking of the blanks, in thesecond forming mill 60 the prefinished blanks with mill run edges ofshort length presents many problems including tolerances, twisting,scuffing of the shelf finish and jamming of the machine. For thesereasons, and according to the present invention, a novel control andedge guide means is provided for the second mill 60.

Referring now to FIG. 4, the rolls associated with the first formingmill 46 are down-forming rolls and when the blank is discharged onto theconveyor section 44 from the last opposing pairs of rolls 70 of the mill46, fragmentarily illustrated, the side flanges 14 project downwardlyand are guided between side rails 72. It is to be noted that the sideflanges 14 of the blanks discharged from these rolls 70 are completelyformed, but the short strip portions 36 remain unformed and remain inthe plane of the blank.

These partially formed blanks 10 progress endwise, i.e. in the directionof their length, to the turn-over device 50 which is indexedintermittently and in timed relation with the arrival of blanks theretoso that the blanks enter pockets 74 which are established betweenadjacent groups of radial arms 52. These arms project radially outwardlyfrom a hub 76 carried on a shaft 78 which projects into a gear box 80mounted on the stationary framework 8-2 of the conveyor 54. The gear box80 is connected through a long coupling shaft 84 to a second gear box 86(FIGS. 4 and wherein the shaft is coupled to an intermittently operateddrive shaft 88 for the conveyor 54. The drive shaft carries a series ofsprockets 90 which are connected by chains 92 to respective sprockets 94secured to and rotatable with the shaft 78.

The details of the control means for intermittently actuating theturn-over device 50 and the conveyor 54 in timed relationship forms nopart of the present invention but various means are usable. If desired,either a photocell or a proximity switch may be employed to detect thedeposition of a shelf blank in position within a pocket 74 whichregisters with the conveyor 44, at which time the turn-over device 50 isindexed one position at a time to bring another pocket into registerwith the conveyor 44 and elevate the previously deposited shelf blankfrom register with the conveyor. This provides a convenient station forinspection with or without removal.

Upon successive indexing operations, the shelf blanks are ultimatelyturned over so that the downturned side flanges 14 become upturned whenthe shelf blanks are deposited laterally on the conveyor 54. The speedof the conveyor 54 is preferably relatively great but in any event, itis such that a shelf blank 10 deposited on the conveyor 54 will clearthe radial arms 52 which carry a succeeding shelf blank at the time theydeposit such blank on the conveyor at mass production speeds.

It is to be noted at this point that because the conveyor 54 extends ata right angle to the conveyor 44, and because the turn over device 50does not change the longitudinal direction of the shelf blanks 10 duringthe transfer operation, the blanks are deposited square to and on theconveyor 54 with their short dimension extending in the direction oftravel and, as previously stated, with the longitudinal side flanges 14projecting upwardly and the rim flanges 24 downwardly.

Referring now to FIG. 5, edge guiding of the shelf blanks 10 along theconveyor 54 is not critical and simple guide rails 96 along the sides ofthe conveyor with wide tolerances suffice to maintain the shelf blankssubstantially centered during their travel along the conveyor. The exitend of the conveyor 54 registers with the entrance end of the conveyor56 and this latter conveyor is comprised of a pair of conveyor chains 98and a series of guide rail devices the nature of which will be describedpresently.

The framework 82 is common to the two conveyors 54 and 56 and it extendsfrom the turn-over device 50 to the second forming mill and includesside frame members 109. The speed of the conveyor chains 98 isappreciably less than the speed of the conveyor chains 92 and the chains98 are supported upon driving sprockets 102, driven end sprockets 104,and a series of idler sprockets 106 which support the reach sections ofthe conveyor chains. The sprockets 102 are driven in unison with therolls associated with the first stand of the second forming mill 69 in amanner that will be described after the nature of this forming mill hasbeen made clear.

The end sprockets 104 are rotatable on studs 103 mounted on supportingrails and they are sufficiently close to the sprockets 92 that thechains 93 will receive the leading edges of the shelf blanks 10thereover after an appreciable degree of overhang from the chains 92takes place. Adjustable stops 112 are secured to the rails 110 to blockany tendency for a shelf blank to fall between the exit end of theconveyor 54 and the entrance end of the conveyor 56 in the event of amachine slowdown or stall. The idler sprockets 106 are similarlysupported on studs 114 carried by the supporting rails 110. Hold downrails 115 are afiixed to the guide rails 96 and overlie the supportingrails 110 in close superimposed relationship. These hold down rails areprovided with bevelled forward end regions 116 for initialblank-centering purposes as will be described presently.

Except for special considerations associated with the first station ofthe second forming mill 60, the mill rolls may be of conventionaldesign. Only the first three stations of this forming mill have beenillustrated in FIG. 5, these three stations being designated at 120, 122and 124. Each station includes opposing pairs of blank-engaging rolls,mounted on upper spindles 126 and lower spindles 128. The rolls areprovided with hub portions 129 and are power driven in unison byinternal gearing disposed within the side structures 130 and 132 of themill 60. The previously mentioned driving sprockets 102 of the conveyor56 are mounted on the hub portions 129 and are driven by the lowerspindles 128 of the first stand 120. Thus the conveyor chains 98 aredriven in timed relation with the various pairs of rolls at thesuccessive mill stands.

As shown in FIGS. 6, 7 and 8, the upper and lower blank-engaging rollsat the first station 120 are designated at 1410 and 142; the rolls atthe second station 122 being designated at 144 and 146; and those at thethird station 124 being designated at 148 and 151 The rolls 140 and 142are blank-gripping and feeding rolls, while all of the rolls at theremaining station of the mill 60 are progressive blank-forming rolls.All of the rolls engage only the short strip portions 36 of the blanks,and opposing pairs are adjustable en banc towards and away from eachother for different shelf widths.

It is essential to a full understanding of the present invention thatthe manner in which the successive blanks are fed to and through thesecond forming mill 6% be understood. Since these blanks are relativelyshort in their direction of travel along the conveyor 56 and arerelatively long in a direction transversely of the direction of travel,great care must be exercised in guiding them from the conveyor 54 alongthe conveyor 56 to the first stand 120 of the second forming mill 6d sothat they will enter such stand squarely. Thereafter, care must be takento maintain accurate alignment of the blanks as they travel through themill.

As previously described, the blanks 1t approaching the mill 60 on theconveyor 56 are inverted, which is to say that the previously formedlong marginal side flanges 14 (FIG. 2) now project vertically upwardlyand extend transversely of the direction of travel of the blanks asshown in dotted lines in FIG. 5. The laterally projecting and yetunformed short strip portions 36 (FIG. 3) are caused to rest and slideupon the upper edges of the supporting rails 110. The level of supportfor the strip portions is slightly above the level of the upper reachportions of the conveyor chains 18 so that the rim flanges 24 contactthe conveyor chains 98 for impelling the shelf blanks 10 forwardlytoward the mill 6!). In moving for wardly under the influence of thechains 98, the laterally projecting strip portions 36 of the blanks 10enter the narrow slot or space existing between the hold down rails 115and the supporting rails 110 while the squared terminal end edges of thecompound flanges 14 of the blanks 10 are closely confined between andare guided by the inside opposed edges of the rails 115. The freeexposed side edges of the strip portions 36 are not confined and thestrip portions 36 therefore pass freely along the slot existing betweenthe rails 110 and 115 subject only to close guiding tolerances at thesquared end edges of flanges 14. The bevelled portions 116 of rails 115initially engage the terminal end edges of the formed side flanges 14 ofthe blanks 16' and effect initial centering of the blank between therails 115. These latter rails thus constitute the sole guiding means forthe blanks in travelling along the conveyor 56 to the mill 60.

The speed of the intermittently operated conveyor 54 is appreciablygreater than that of the continuously operable conveyor 56. The blanks10 are thus projected by the conveyor 54 onto the conveyor 56successively and with appreciable momentum -to assure clearance of theradial arms 52 and the chains 98 move the blank into roller grippingposition. Thereafter the movement of the blanks along the conveyor 56 issomewhat slower and uniform.

Heretofore, in connection with conventional mills such would otherwisebe used at mill 60 for the shaping of the lateral short end edges ofblanks, it has been impossible to effect proper tracking of the shelfblanks through the mill rollers unless the projecting planar end edgeregions, i.e., the short strip portions 36 (FIG. 3) are of uniformwidth. The slightest discrepancy between the widths of these mill edgestrip portions on opposite sides of the mill will cause cocking ortwisting of the blanks and a consequent jamming of the machine. This hasbeen because ordinarily the first set of rolls encountered are formingrolls and have bevelled forming surfaces which engage the strip portions36 unequally. A strip portion 3s wider on one end edge of the blank thanthe one on the other end edge will preempt this strip portion to rideoutwardly on the frusto-conical portions of the forming rolls and thusbe propelled on a greater driving radius than obtains on the other sideof the mill. Cocking of the blank will result regardless of howaccurately aligned the blank may be when it enters the mill.

According to the present invention, to obviate such twisting of theblanks, even when wide tolerances in the widths of the strip portions 36are to be expected by reason of the use of mill width steel, the rolls140 and 142 at the first stand (FIG. 6) are truly cylindrical and theyexert a relatively powerful gripping action on the strip portions 36 asthey initially enter the mill. The rolls 144 and 146 at the second stand122 are forming rolls and they are shown in FIG. 7 as being providedwith complementary frusto-conical forming surfaces 160. The short stripportions 36 of the blanks 10 which are initially fed to these formingrolls 144 and 146 remain firmly engaged by the gripping r-olls 14d and142 during passage of the strip portions 36 through the rolls 144 and146 and thus, although the tendency for the blank to twist remainsprevalent, the gripping rolls and 142 which engage the trailing regionof the blanks, hold the blanks against such twisting until such time asengagement by the forming rolls 148 and at the third station 124 (FIG.8) take over. At the time that the blanks thus reach the third stand ofthe mill 60, the danger of twisting or cocking of the blanks has largelypassed. An appreciable bend has been applied to the short strip portions36 and the trailing regions of these partially formed strip portions arefirmly seized by the forming rolls 144 and 146 at the second stand 122at the time that the leading edge of the blank arrives at and is engagedby the forming rolls 148 and 150 at the third station 124. As shown inFIG, 8, these latter forming rolls 148 and 150 are provided with radialmating forming surfaces 161. At successive stands of the mill 60additional forming operations take place but, since an appreciabledegree of rigidity has been applied to the originally flat stripportions 36, accurate tracking of the blanks throughout the remainder oftheir travel through the mill 60 will be maintained.

A pair of guide rails 162 extend between the various upper and lowerspindles 126 and 128 and support the blanks near the working areasthereof during their passage through the mill 60. These latter guiderails have lateral extensions 164 which project laterally between therolls of adjacent stands and prevent the strip portions 36 fromattempting to curl around the forming rolls.

The invention is not to be limited to the exact arrangement of partsshown in the accompanying drawings or described in this specification asvarious changes in the details of construction may be restorted towithout departing from the spirit of the invention. Therefore, onlyinsofar as the invention has particularly been pointed out in theaccompanying claims is the same to be limited.

What is claimed is:

1. In a successively operable, shelf-forming apparatus forsimultaneously bending, by progressive rolling operations, oppositelydirected narrow coplanar strip portions which project outwardly at theopposite ends of partially formed longitudinally elongated generallyrectangular sheet metal shelf blanks to produce compound transverselyextending marginal lateral flanges at the ends of the blanks, the blankshaving previously been formed with longitudinally extending marginallateral side flanges which terminate short of the strip portions, incombination, a forming mill establishing a linearly straight workingarea through which the blanks are adapted to pass sidewise, a series ofsuccessively arranged opposed identical pairs of cooperatingblank-engaging rolls at the opposite sides of said working area, saidopposed pairs of rolls being successively engageable with said coplanarstrip portions and operable to impel the blanks forwardly through theworking area while progressively bending said strip portions to formsaid transversely extending marginal lateral flanges, the firstidentical pair of opposed rolls in the series presenting cooperatingcylindrical blankgripping surfaces, the second identical pair of rollsin the series having cooperating mating frusto-conical blank-engagingsurfaces engageable with the leading edges of said coplanar stripportions prior to release of the trailing edges thereof by the firstidentical pair of opposed rolls, and means for driving said opposedpairs of rolls in unison.

2. In a successively operable shelf-forming apparatus, the combinationset forth in claim 1 and including, additionally, a pair of horizontalblank-supporting rails on opposite sides of said Working area andcoextensive with the latter, said supporting rails presenting uppersupporting surfaces which lie substantially at the horizontal level ofthe blank-engaging surfaces afforded by said pairs of rolls.

3. In a successively operable shelf-forming apparatus for simultaneouslybending, by a progressive rolling operation, oppositely directed narrowcoplanar strip portions which project outwardly at the opposite ends ofpartially formed longitudinally elongated generally rectangular sheetmetal shelf blanks to produce compound transversely extending marginallateral flanges at the ends of the blanks, the blanks having previouslybeen formed with longitudinally extending marginal lateral side flangeswhich terminate short of the strip portions, in combination, a formingmill establishing a linearly straight working area through which theblanks are adapted to pass sidewise, a series of successively arrangedopposed identical pairs of cooperating blank-engaging rolls at theopposite sides of said working area, said opposed pairs of rolls beingsuccessively engageable with said coplanar strip portions and operableto impel the blanks forwardly through the Working area whileprogressively bending said strip portions to form said transverselyextending marginal lateral flanges, the first identical pair of opposedrolls in the series presenting cooperating cylindrical blankgrippingsurfaces, the second identical pair of rolls in the series havingcooperating mating frusto-conical blankengaging surfaces thereonengageable with the leading edges of said coplanar strip portions priorto release of the trailing edges thereof by the first identical pair ofopposed rolls, an endless conveyor for conducting blanks to said workingarea, said conveyor having an upper reach section in horizontalalignment with said working area at the entrance end thereof, at thehorizontal level of the blank-engaging surfaces afforded by said pairsof rolls, and of an effective width slightly less than the width of theworking area, and means for driving said opposed pairs of rolls andconveyor in unison.

4. In a successively operable shelf-forming apparatus, the combinationset forth in claim 3 and including, additionally, a pair of horizontallydisposed opposed cooperating centering guides on opposite sides of saidconveyor and substantially coextensive with the latter, said centeringguides being engageable with the opposite end edges of thelongitudinally extending side flanges of the blanks and constituting thesole centering means for guiding the blanks in their sidewiserelationship into said working area.

5. In a successively operable shelf-forming apparatus, the combinationset forth in claim 3 and including, additionally, a pair of horizontallydisposed opposed cooperating centering guides on opposite sides of saidconveyor and substantially coextensive with the latter, said centeringguides being positioned so as to overhang the coplanar strip portions ofthe blanks passing along said conveyor and to engage the opposite endedges of the longitudinally extending side flanges of the blanks, saidcentering guides constituting the sole centering means for guiding theblanks in their sidewise relationship into said working area, and anadditional pair of guides on opposite sides of the conveyor coextensivewith and spaced vertically from said centering guides a distancesubstantially equal to the thickness of the sheet metal of the blanksand defining, in combination with said centering guides, a narrowelongated slot into which said coplanar strip portions loosely projectand along which they are adapted to slide during travel of the blankstowards said working area.

6. In a successively operable apparatus for simultaneously bending, byprogressive rolling operations, oppositely directed narrow coplanarstrip portions which project outwardly at the opposite ends of apartially formed longitudinally elongated generally rectangular sheetmetal shelf blanks to produce compound transversely extending marginallateral flanges at the ends of the blanks, the blanks having previouslybeen formed with longitudinally extending marginal lateral side flangeswhich terminate short of the strip portions, in combination, a formingmill establishing a linearly straight working area through which theblanks are adapted to pass sidewise with said lateral side flangesprojecting upwardly, a series of successively arranged opposed identicalpairs of cooperating blank-engaging rolls at the opposite sides of saidworking area, said opposed pairs of rolls being successively engageablewith said coplanar strip portions and operable to impel the blanksforwardly through the working area While progressively bending saidstrip portions upwardly to form said transversely extending marginallateral flanges, the first identical pair of opposed rolls in the seriespresenting cooperating cylindrical gripping surfaces, the secondidentical pair of rolls in the series having cooperating matingfrusto-conical blank-engaging surfaces engageable with the leading edgesof said coplanar strip portions prior to release of the trailing edgesthereof by the first identical pair of opposed rolls, an endlessconveyor for conducting blanks to said working area, said conveyorhaving an upper reach section in horizontal alignment with said workingarea at the entrance end thereof, at the horizontal level of theblank-engaging surfaces afforded by said pairs of rolls, and of aneffective width slightly less than the width of said working area, apair of horizontally disposed blank-supporting rails on opposite sides-of said conveyor and having upper surfaces at substantially thehorizontal level of the reach section of the conveyor and on which theblanks are adapted to be slidingly supported, said conveyor impellingthe blanks forwardly along said upper surfaces of the blank-supportingrails, a pair of horizontally disposed cooperating centering guides onopposite sides of the conveyor a slight distance above said rails andpositioned to overlie and overhang the coplanar strip portions of theblanks passing along the conveyor and to engage the opposite end edges:of the longitudinally extending side flanges of the blanks, saidcentering guides constituting the sole centering means for guiding theblanks in their sidewise relationship into said working area, and meansfor driving said opposed pairs of rolls and conveyor in unison.

7. In a successively operable shelf-forming apparatus, the combinationset forth in claim 6 and including, additionally, a pair of horizontallydisposed blank-supporting rails on opposite sides of said working areaand coextensive with the latter, said latter supporting rails presentingupper supporting surfaces which lie substantially at the horizontallevel of the blank-engaging surfaces afforded by said pairs of rolls.

8. In a successively operable shelf-forming apparatus for simultaneouslybending, by progressive rolling operations, oppositely directed narrowcoplanar strip portions which project outwardly at the opposite ends ofpartially formed longitudinally elongated generally rectangular sheetmetal shelf blanks to produce compound transversely extending marginallateral flanges at the ends of the blanks, the blanks having previouslybeen formed with longitudinally extending lateral rim and marginal sideflanges which terminate short of the strip portions, in combination, aforming mill establishing a linearly straight Working area through whichthe blanks are adapted to pass sidewise with said lateral side flangesprojecting upwardly, a series of successively arranged opposed identicalpairs of cooperating blank-engaging rolls at the opposite sides of saidworking area, each pair including upper and lower rollers presentinginwardly directed hub portions, said opposed pairs of rolls beingsuccessively engageable with said coplanar strip portions and operableto impel the blanks forwardly through the working area whileprogressively bending said strip portions upwardly to form saidtransversely extending marginal lateral flanges, the first identicalpair of opposed rolls in the series presenting cooperating cylindricalgripping surfaces, the second identical pair of rolls in the serieshaving cooperating mating frusto-conical blank-engaging surfacesengageable with the leading edges of said coplanar strip .portions priorto release of the trailing edges thereof by the first identical pair ofopposed rolls, an endless conveyor for conducting blanks to said workingarea, said conveyor including a pair of blank-impelling chains andhaving upper reach sections in alignment with the rolls on oppositesides respectively of said working area to engage said rim flanges,driving sprockets for said chains on the hub portions of the lowerrollers of the first opposed pair of blank-engaging rolls, and means fordriving said opposed pairs of rolls in unison.

9. In a successively operable shelf-forming apparatus, the combinationset forth in claim 8 and including, additionally, a pair of horizontallydisposed blank-supporting rails on opposite sides of said conveyor andhaving upper surfaces at substantially the horizontal level of the reachsections of the conveyor chains and on which the blanks are adapted tobe slidingly supported, and a pair of horizontally disposed cooperatingcentering guides on opposite sides of the conveyor a slight distanceabove said rails and positioned to overlie and overhang the coplanarstrip portions of the blanks passing along the conveyor and to engagethe opposite end edges of the upwardly projecting longitudinallyextending side flanges of the blanks, said centering guide-sconstituting the sole centering means for guiding the blanks in theirsidewise relationship into said working area.

10. A method of formng a generally rectangular sheet metal shelf havinga rectangular planar body :portion provided with marginal dependinglongitudinal side flanges and transverse end flanges, said methodcomprising: removing the four corner regions of a flat rectangular sheetmetal blank by cutting rectangular notches therein by a metal removingoperation so as to provide said rectangular planar body portion andestablish elongated narrow rectangular strip portions along thelongitudinal side edges of said body portion and in the plane thereof,and short narrow strip portions along the transverse end edges of saidbody portion and in the plane thereof, passing the thus notched blankendwise and in the plane of said body portion through successive opposedpairs of forming rolls and causing said elongated narrow rectangularstrip portions along the longitudinal edges of said body portion to berolled downwardly out of the plane of the body portion to produce saidmarginal depending longitudinal side flanges, moving the blank laterallyso that said side flanges are disposed normal to the line of blankmovement, and passing the blank sidewise and in the plane of said bodyportion through successive opposed pairs of forming rolls and guidingsaid short narrow strip portions solely from contact with the ends ofsaid side flanges along the transverse end edges of said body portion tobe rolled out of the plane of the body portion to produce said marginaltransverse end flanges.

11. The method called for in claim 10 including engaging said shortnarrow strip portions with a rolling feed clamped relationship whilesaid blank is being guided by said contact with the ends of the sideflanges.

No references cited.

WILLIAM W. DYER, IR., Primary Examiner. L. VLACHOS, Examiner.

10. A METHOD FOR FORMING A GENERALLY RECTANGULAR SHEET METAL SHELFHAVING A RECTANGULAR PLANAR BODY PORTION PROVIDED WITH MARGINALDEPENDING LONGITUDINAL SIDE FLANGES AND TRANSVERSE END FLANGES, SAIDMETHOD COMPRISING: REMOVING THE FOUR CORNER REGIONS OF A FLATRECTANGULAR SHEET METAL BLANK BY CUTTING RECTANGULAR NOTCHES THEREIN BYA METAL REMOVING OPERATION SO AS TO PROVIDE SAID RECTANGULAR PLANAR BODYPORTION AND ESTABLISH ELONGATED NARROW RECTANGULAR STRIP PORTIONS ALONGTHE LONGITUDINAL SIDE EDGES OF SAID BODY PORTION AND IN THE PLANETHEREOF, AND SHORT NARROW STRIP PORTIONS ALONG THE TRANSVERSE END EDGESOF SAID BODY PORTION AND IN THE PLANE THEREOF, PASSING THE THUS NOTCHEDBLANK ENDWISE AND IN THE PLANE OF SAID BODY PORTION THROUGH SUCCESSIVEOPPOSED PAIRS OF FORMING ROLLS AND CAUSING SAID ELONGATED NARROWRECTANGULAR STRIP PORTIONS ALONG THE LONGITUDINAL EDGES OF SAID BODYPORTION TO BE ROLLED DOWNWARDLY OUT OF THE PLANE OF THE BODY PORTION TOPRODUCE SAID MARGINAL DEPENDING LONGITUDINAL SIDE FLANGES, MOVING THEBLANK LATERALLY SO THAT SAID SIDE FLANGES ARE DISPOSED NORMAL TO THELINE OF BLANK MOVEMENT, AND PASSING THE BLANK SIDEWISE AND IN THE PLANEOF SAID BODY PORTION THROUGH SUCCESSIVE OPPOSED PAIRS OF FORMING ROLLSAND GUIDING SAID SHORT NARROW STRIP PORTIONS SOLELY FROM CONTACT WITHTHE ENDS OF SAID SIDE FLANGES ALONG THE TRANSVERSE END EDGES OF SAIDBODY PORTION TO BE ROLLED OUT OF THE PLANE OF THE BODY PORTION TOPRODUCE SAID MARGINAL TRANSVERSE END FLANGES.